Vapor-permeable shoe

ABSTRACT

A vapor-permeable shoe comprising the following combination of elements: a vapor-permeable upper ( 11 ) associated with a vapor-permeable or perforated lining ( 12 ); a tread sole ( 13 ) made of perforated elastomer; a mid-sole, comprising at least one membrane ( 15 ) made of waterproof and vapor-permeable material associated with a lower protective layer ( 16 ) made of a material resistant of hydrolysis, the layer being water-repellent, vapor-permeable and/or perforated; a vapor-permeable or perforated insole ( 17 ); a vapor-permeable or perforated filler ( 19 ) layer arranged between said insole and said membrane. The membrane is associated and sealed, at its edge regions, to a pre-molded insert ( 14 ) which is suitable to form a perimetric support for the membrane both during assembly and during use.

This application is a continuation of application Ser. No. 09/423,299filed Nov. 9, 1999, now U.S. Pat. No. 6,389,711 which is a 371 ofPCT/EP98/02537 filed Apr. 29, 1998.

TECHNICAL FIELD

The present invention relates to an improved vapor-permeable shoe.

BACKGROUND ART

It is currently known that a shoe, in order to be comfortable, mustensure correct exchange of heat and water vapor between the microclimateinside the shoe and the external microclimate.

However, such heat and water-vapor exchanges must not compromise in anycase the impermeableness of the shoe to external moisture or water.

In currently commercially available shoes, heat and water-vaporexchanges are substantially entrusted either to the upper portion of theshoe (upper) or to the sole.

As regards the upper portion of the shoe, shoes which have perforateduppers and/or are provided with linings made of vapor-permeable andwaterproof material are currently commercially available.

Indeed, in some models, part of the upper may be replaced with materialswhich are indeed waterproof and at the same time vapor-permeable.

Another category of shoes instead entrusts transpiration to the sole, byusing layers of materials which are impermeable to water and arevapor-permeable, optionally associated with protective layers and withfillers.

In order to achieve optimum exchange of heat and water vapor, avapor-permeable shoe has been conceived which is disclosed in ItalianInvention Patent Application No. PD95A000190 filed on Oct. 13, 1995 andcomprises the following combination of elements:

a vapor-permeable upper associated with a vapor-permeable or perforatedlining;

a tread sole made of perforated elastomer;

a mid-sole which comprises at least one membrane made of vapor-permeablewaterproof material which is associated with a lower protective layermade of a material resistant to hydrolysis, water-repellent andvapor-permeable or perforated;

a vapor-permeable or perforated insole;

a vapor-permeable or perforated filler layer arranged between the insoleand the membrane.

In the shoe as disclosed in Italian Invention Patent Application No.PD95A000190 filed on Oct. 13, 1995, the lower part of the upper, thethread sole and the mid-sole with the membrane are perimetrically sealedin their coupling regions. Said shoe has solved the problem of thetranspiration of heat and water vapor, but it still entails somemarginal drawbacks mostly during manufacture. This is because it israther difficult to insert the rather delicate waterproof membraneprecisely, safely and without damage during the assembly of themid-sole.

Moreover, during use, the membrane, especially in shoes used inparticularly demanding situations, may be subjected to such stresses asto produce undesirable damage thereto.

The aim of the present invention is to provide a vapor-permeable shoewhich combines the possibility of providing heat and water-vaporexchange both through the upper and through the sole, ensuring at alltimes an optimum internal microclimate as a function of the externalclimate, with improved simplicity and precision of execution duringmanufacture.

Within the scope of this aim, an object of the present invention is toprovide a vapor-permeable shoe in which the membrane specificallyassigned to the transpiration function is protected effectively even ifthe shoe is used in situations which are particularly demanding as tomechanical stresses, such as in the field of sports and in the field ofworking shoes.

Another object of the present invention is to provide a vapor-permeableshoe which is meant both for day-to-day use and for sports use.

Another object of the present invention is to provide a vapor-permeableshoe having a competitive cost with respect to conventionalvapor-permeable shoes.

Another object of the present invention is to provide a vapor-permeableshoe which can be manufactured with known technologies.

This aim, these objects and others which will become apparenthereinafter are achieved by a vapor-permeable shoe comprising thefollowing combination of elements:

a vapor-permeable upper which is associated with a vapor-permeable orperforated lining;

a tread sole made of perforated elastomer;

a mid-sole which comprises at least one membrane made of waterproof andvapor-permeable material which is associated with a lower protectivelayer made of a material resistant to hydrolysis, water-repellent andvapor-permeable and/or perforated;

a vapor-permeable or perforated insole;

a vapor-permeable or perforated filler layer arranged between saidinsole and said membrane,

said shoe being characterized in that said membrane is arranged in apreassembled insert, to which it is sealed at its edge regions, saidinsert being suitable to provide support for said membrane both duringassembly and during use.

This invention also concerns a vapor-permeable, water-repellant orwaterproof, preassembled insert capable of being precisely and easilyincluded into a sole assembly during manufacture of a shoe. The insertcomprises a vapor-permeable, waterproof membrane having upper and lowerfaces and an edge face, a vapor-permeable or perforate protective layeradjacent to and in contact with said lower face, and a waterproofsupporting grid adjacent to and in contact with said membrane, saidsupporting grid being bonded to said membrane at least at the peripheryof said membrane. The bonding may be accomplished at the perimeter ofsaid upper face of said membrane, at the perimeter of said edge face orat the perimeter of both said upper face and said edge face.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the vapor-permeable shoeaccording to the present invention will become apparent from thefollowing detailed description of various embodiments thereof,illustrated by way of non-limitative example in the accompanyingdrawings, wherein:

FIG. 1 is a transverse sectional view of a shoe according to theinvention in a first embodiment;

FIGS. 2 to 5 are sectional views of respective variations of an insertincluded within the shoe of FIG. 1;

FIG. 6 is a sectional view of another variation of the insert and of thetread sole of the shoe of FIG. 1;

FIGS. 7 and 8 are sectional views of possible embodiments of the treadsole including a membrane;

FIG. 9 is a transverse sectional view of another variation of the shoeaccording to the present invention;

FIG. 10 is a view of a variation of the tread sole with protectivemembrane;

FIG. 11 is a transverse sectional view of a shoe according to theinvention in another embodiment;

FIG. 12 is an enlarged-scale view of a detail of FIG. 11.

WAYS OF CARRYING OUT THE INVENTION

With particular reference to FIG. 1, a vapor-permeable shoe according tothe invention is generally designated by the reference numeral 10 in afirst embodiment.

In this case, the shoe 10 comprises an upper 11 which is vapor-permeable(for example made of natural hide without sealing pigments), associatedwith a lining 12 which is vapor-permeable or perforated (for examplemade of Cambrelle).

The lining 12 is associated with the upper 11 by spot gluing so as toavoid compromising transpiration through said upper.

The shoe 10 further comprises a tread sole 13 made of elastomer, whichis perforated in a downward region, and a mid-sole which is generallydesignated by the reference numeral 14.

In this case, the mid-sole 14 comprises a membrane 15 made ofvapor-permeable waterproof, Teflon material, such as those commerciallyavailable and known by the trade-name Gore-Tex, associated with aprotective layer 16 which is directed towards the tread sole 13 and ismade of a material resistant to hydrolysis, water-repellent,vapor-permeable or perforated. Alternatively, the vapor-permeablewaterproof material may be polyurethane or a polyester commerciallyavailable and known by the trade-name Sympatex.

Membranes used to prepare the vapor-permeable, waterproof materialgenerally have a thickness in the range of 10 to 50 microns. Suchmembranes are usually sold by the manufacturer as coated large meshedand light “tricots”.

Protective layers for the waterproof film may be formed of fast dryingnon-woven fabric, e.g. polyester having a thickness ranging from 0.8 to5 millimeters thick. For conventional shoes, a thickness of 1 millimeteris satisfactory. For shoes used in heavy duty applications, such astrekking and working boots, a protective layer thickness of 4 to 5millimeters or more is satisfactory.

The shoe 10 further comprises, in this case, an insole 17 made ofvapor-permeable material (for example natural leather) which isperforated and is optionally associable with a heel seat made of softhide with absorbent rubber latex, not shown. The insole 17 is applied tothe upper 11 through the classic system called “lasting”, that isthrough a “cap-like”, matching of a spreaded upper to a last, to whichan insole is applied with nails in the area of the sole. Then, throughstretching and spreading, the perimetric parts of the upper are glued onthose of the insole along the entire perimeter of the insole. In thisway, the upper takes the shape of the last. The outsole or tread sole 13is then applied.

In this first embodiment, according to the invention, the mid-sole 14 isa pre-molded or in any case preassembled insert to which the tread sole13 is joined by gluing with a perimetric sealing action or byovermolding.

Said insert/mid-sole 14 which in this case comprises not only themembrane 15 and the protective layer 16 but also a supporting/sealingelement 19 which affects the upper and edge regions of the membrane 15,has through holes 19 a in its upper region and acts as a filler layer.

The membrane 15 and the protective layer 16 are sealed at the edgeregions to the element 19, which is made of elastomeric material (forexample polyurethane) and is suitable to form a support for saidmembrane both during assembly and during use. The attachment may be byovermolding without glues. Similar results may be achieved by a)pre-molding or pre-shaping of the element 19 and subsequent waterproofgluing to the membrane 15, b) superinjection or high frequency orultrasound welding with the help of liquid glues (e.g.,single-component, hydrolysis-resistant polyurethane) or solid, thermicor electro-weldable glues (films).

In this embodiment it is also possible to apply to the shoe 10 a tip,not shown, which is vapor-permeable or perforated and is associated withthe upper 11 by means of spots of glue so as to ensure its transpirationproperties.

Likewise, a vapor-permeable or perforated rear counter, also not shown,can be associated with the upper 11 by means of spots of glue.

The upper 11, in this case, is associated with the insole 17 by applyinga bond-like layer of glue along the perimeter of the insole.

Limiting the gluing layer to a perimetric band preserves thevapor-permeability of most of the surface of the insole.

Thus, in the shoe 10, the central part of the insole is in fact entirelyfree of any element which is impermeable to water vapor (i.e.,non-vapor-permeable).

The membrane 15 and the lower protective layer 16 are mutually coupledby spot gluing by using an adhesive which is commercially available andis resistant to hydrolysis (a kind commonly known as “hot melt”, orsystems with calendered powders).

The protective layer 16 can be conveniently made of water-repellentmaterial which is capable of drying quickly. Such material includes forexample non-woven fabric, preferably polyester, needle-loomed fabric orKevlar.

The protective layer 16 is directed downward, i.e., towards the treadsole 13, since it must protect the membrane 15 against external impactsor foreign objects which might penetrate through the holes formed insaid tread sole 13.

Moreover, the membrane 15 is substantially sealed perimetrically by theconnection to the element 19, which is overmolded thereon duringproduction. Alternatively, the seal can be produced by perimetric gluingof the upper perimetric surface and/or edge of membrane 15 to element 19with hydrolysis-resistant adhesives.

Therefore, the connection between the membrane 15 and the element 19occurs either without using adhesives, or with adhesives only in theperimetric part. This affords ample surface of the membrane free ofcovering or coating so as to permit transpiration of moisture vapors.

Moreover, the entire insert/mid-sole 14 can be provided so as to bemodular, being usable for various soles and for various sizes. Ifdesired the inserts may be shaped to accommodate the shape of “left” and“right” shoes.

Moreover, it is noted that the insert/mid-sole 14 is easy to insert inthe sole, thus facilitating the positioning of the membrane 15, whichcan be applied with absolute precision.

Similarly, the treed sole 13 may be shaped to accommodate the insert.Precision in positioning is in fact assisted by the very shape of theinsert/mid-sole 14, which is perimetrically shaped substantiallycomplementary to the remaining components of the sole in or betweenwhich it must be accommodated.

The assembly of the membrane 15 allows to leave the largest possiblevapor-permeable surface without having superimposed elements thereon,consequently increasing the absorbing capabilities of the membrane 15.

With particular reference to FIG. 2, in a constructive differentembodiment of the shoe 10 the insert, now designated by the referencenumeral 114, comprises a supporting grid 121 above the membrane 115 withthe protective layer 116, while the overmolded or superimposed element,now designated by the reference numeral 119, is limited only to theperimetric regions.

The grid 121 gives greater mechanical strength to the shoe, particularlyat the insole. If desired the grid 121 may be separately overmolded ontoor separately adhered to the membrane or may be an integral portion ofsuperimposed element 114.

With particular reference to FIG. 3, in another different embodiment ofthe shoe 10 the insert, now designated by the reference numeral 214,comprises, above the membrane 215, a felt 222 (or another highlyvapor-permeable filler material in other cases) which is applied in themold or subsequently and has high-level characteristics in terms ofvapor-permeability, moisture absorption, physical weight support andthermal insulation from the outside climate; said characteristics areparticularly useful for example in winter shoes, where it is necessaryto prevent condensation of the water vapor produced by perspiration dueto its cooling.

In particular, in shoes meant for cold environments, the felt 222 or thematerial having similar characteristics can be combined with films orlayers of material which are highly insulating and vapor-permeable orsuitably perforated to ensure vapor permeability.

In this case too, the overmolded element 219 affects only the edgeregions of the membrane 215 and of the protective element 216.

With reference to FIG. 3 b is, the filler layer, now designated by thereference numeral 222 a (and made for example of felt), is interposedbetween an upper spacing layer 222 b made of hydrophobic material and alower layer 222 c made of hydrophilic material, both of which areperforated or vapor-permeable.

In this manner, an increase in the absorbing capabilities of themembrane, now designated by the reference numeral 215 a is achieved, andtherefore in the vapor-permeability of the shoe through the sole.

The layer 222 b made of hydrophobic material is in fact meant to propelmoisture towards the layer 222 c made of hydrophilic material which liesclose to the membrane 215 a on the opposite side with respect to theprotective layer 216 a, allowing it to absorb said moisture quickly andto expel it outside, preventing the vapor, before passing through themembrane 215 a, from condensing into water, which does not pass throughand stagnates inside the shoe.

As an alternative, the two hydrophobic and hydrophilic layers can alsoenclose, in a sandwich-like fashion; other elements arranged between thefoot and the membrane (insole, supports located outside the membrane,etcetera).

It is evident from the illustrations set forth in FIGS. 1, 2, 3 and 3 bis that the supporting/sealing element 19, 119, 219 may abut theperimetric outer surface of the waterproof membrane, the perimetric edgeface of the membrane and the perimetric edge of the protective layer.

With particular reference to FIG. 4, in another different embodiment, inthe insert 314 the means for protecting the membrane 315, which is knownto be particularly sensitive and susceptible of damage at rough terrainor at foreign objects which can pass through the holes of the treadsole, are constituted, in this case, by one or more elements 316 made ofopen-cell plastics (for example, materials such as polyurethane orpolyethylene or polyester are commercially available), which can offergreat resistance to perforation by virtue of their thickness, rigidityand physical characteristics.

The element 316 is also provided in practice with through holes havingvarious orientations, so as to prevent foreign objects from makingcontact with the membrane 315.

The insert 314 is completed along its perimeter by an element 319 whichis overmolded or superimposed like the preceding ones.

With particular reference to FIG. 5, in a further embodiment of theinsert, now designated by the reference numeral 414, the means forprotecting the membrane 415 are constituted by one or more elements 416made of felt which is in turn constituted by fibers resistant toperforation, such as aramid fibers or equivalent fibers.

In this case too, the insert 414 is completed by an element 419 which isovermolded or superimposed.

FIG. 6 depicts another embodiment of the insert, now designated by thereference numeral 514, it has a sandwich-like structure which comprisestwo external membranes 515 a and 515 b made of waterproof andvapor-permeable material and between which a vapor-permeable and/orperforated structural supporting element 516 is packed.

The membranes 515 a and 515 b are mutually glued with water-resistantadhesives so as to form a perimetric seal. In this embodiment, inparticular, the membrane 515 b is more exposed than the other to anydamaging action; however, the more protected membrane 515 a in any caseensures vapor permeability and yet provides waterproofing of the shoe asa whole, while the other membrane is protected to a certain extent byoptional contouring of the tread sole, designated by the referencenumeral 513 in this case, to which it is perimetrically sealed or whichis overmolded or superimposed thereon.

In particular, optional protective contours of the tread sole arevisible in FIGS. 7 and 8, which show two tread soles, designated by thereference numerals 613 a and 613 b respectively, in which the holes,designated by the reference numerals 620 a and 620 b respectively, arespaced from the region that is in contact with the ground for example byincreasing the thickness of the pattern of said tread sole but not theminimum thickness of the material in the perforation points.

The reference numerals 615 a and 615 b designate the respectivemembranes.

It should also be noted that in further embodiments the pre-moldedinsert can also comprise portions of the tread sole.

With particular reference to FIG. 9, a constructive variation of theshoe is fully similar to the shoe 10 and is thus generally designated bythe reference numeral 700.

In this embodiment, the shoe 700 is provided with means for protectingthe membrane 715, which are constituted by a composite tread sole 713.

In particular, the tread sole 713 comprises a waterproof layer 713 a,which is in contact with the ground, and an internal layer 713 b, whichis made of microporous and fully permeable material.

In particular, said layer 713 b makes contact with, or in any casefaces, the membrane 715, to which it is joined at least in the edgeregions (where a seal is provided) by means of an element 720 whichjoins the entire assembly to the upper 711.

The layer 715 b is fully permeable and thus allows the transpiration ofwater vapor and heat exchange through its edge regions (the otherregions are sealed by the lower layer 715 a).

The shoe has, above the membrane 715 as well, a filler layer 719 whichis vapor-permeable or perforated and a vapor-permeable or perforatedinsole 717.

With particular reference to FIG. 10, a tread sole in a furtherembodiment is generally designated by the reference numeral 813.

The tread sole 813 has a structure which is substantially similar to thetread sole 13; however, it differs from said structure in that itcomprises a membrane 815 which is made of vapor-permeable and waterproofmaterial and is applied to a lower protective layer 816.

The membrane 815 and the protective layer 816 are folded and sealedperimetrically directly to the tread sole 813, which is in any caseperforated.

In this case, therefore, the membrane 815 is sealed directly to thetread sole 813.

Coupling to the remaining parts is provided for example as in the caseof the shoe 700.

With particular reference to FIGS. 11 and 12, a shoe according to theinvention, in another embodiment, is generally designated by thereference numeral 900.

The shoe 900 is particularly suitable for safety applications in worksubjected to the risk of intense continuous or momentary stressesaffecting the feet.

In particular, the shoe 900 has a structure which is substantiallysimilar to the shoe 10, but it differs from the latter in that itcomprises a metallic element 902 which is inserted in the mid-sole,designated by the reference numeral 901 in this case, which is contouredand corrugated so as to increase its structural strength and is providedwith holes 903 in which the axis is substantially parallel to the groundand which allow continuity of the vapor-permeability of the shoe 900 asa whole.

As an alternative to the metallic material it is possible to use adifferent material having the same strength characteristics, such ascarbon fiber, fiber-reinforced plastics, etcetera.

In particular, in this case the metallic element 902 is arrangeddirectly below a membrane 915 which is meant to simultaneously providethe vapor-permeable and waterproofing function.

The membrane 915, together with the corrugated element 902, a lowerfiltering element 917 and a portion 919 a of perforated tread sole 913which is overmolded and seals the perimetric regions, are part of apre-molded or superimposed insert 914.

An upper filler layer 918 is provided.

The assembly is joined to the rest of the shoe 900 by means of theremaining (perimetric) portion 919 b of the tread sole 913, which isovermolded or superimposed.

Vapor-permeability in this shoe occurs for example along the path of thedouble arrow 920.

In practice, it has been observed that the present invention, in itsvarious embodiments and variations, achieves the intended aim andobjects.

In particular, it should be noted that the shoe and insert according tothe invention substantially completely solve any difficulties inpositioning the membrane during manufacture.

Moreover, the shoe and insert according to the invention also providefor adequate protection of said membrane; accordingly, shoes so preparedcan be used also for particularly demanding applications, as for examplein the sports field or in the field of safety footwear.

It should also be noted that membrane protection is achieved withoutcompromising in any way the vapor-permeability and waterproofingcharacteristics of the shoe as a whole.

Attention is also drawn to the flexibility of use of the shoe accordingto the invention and to the possibility of providing said shoe at costswhich are highly competitive with respect to conventional shoes.

It should also be noted that the shoe according to the invention, thanksto its shape and constructive structure, can also be suitable forhigh-quality embodiments.

The present invention is susceptible of modifications and variations,all of which are within the scope of the inventive concept; thematerials may also be any according to requirements.

Obviously, numerous modifications and variations of the presentinvention are possible in light of the above teachings. It is thereforeto be understood that within the scope of the appended claims theinvention may be practiced otherwise than as specifically describedherein.

This application claims priority of Italian Application No. PD97A000102filed May 9, 1997, the entire specification of which is incorporatedherein by reference.

1. A shoe comprising: an upper; a tread sole; and at least one membranemade of waterproof and vapor-permeable material and positioned over saidtread sole; wherein said tread sole comprises a composite having awaterproof lower layer for contact with the ground and a moisturepermeable upper layer facing said membrane, and said moisture permeableupper layer is positioned such that said moisture permeable upper layertranspires at a perimetric lateral edge to exterior and at a lateraledge to said at least one membrane.
 2. The shoe of claim 1, wherein saidwaterproof lower layer comprises elastomer.
 3. The shoe of claim 1,wherein said moisture permeable upper layer comprises microporous andfully permeable material which allows transpiration of water vaporthrough said perimetric edge.
 4. The shoe of claim 1, wherein saidwaterproof lower layer makes contact with said at least one membrane towhich said waterproof lower layer is joined at least in edge regionsthereof where a seal is provided by an element which joins the entireassembly to said upper.
 5. The shoe of claim 1, said upper isvapor-permeable.
 6. The shoe of claim 1, further comprising: avapor-permeable insole; and a vapor-permeable filler layer arrangedbetween said vapor-permeable insole and said at least one membrane. 7.The shoe of claim 1, wherein said moisture permeable upper layer ispermeable to heat allowing heat exchange through said perimetric edgethereof.
 8. A shoe comprising: an upper; at least one membrane providedunder the upper and comprising waterproof and vapor-permeable material;and a tread sole provided under the at least one membrane and comprisinga composite having a waterproof lower layer for contact with the groundand a moisture permeable upper layer configured to allow transpirationat a perimetric edge to exterior and at a lateral edge to the at leastone membrane, the moisture permeable upper layer facing the at least onemembrane.
 9. The shoe of claim 8, wherein said waterproof lower layercomprises elastomer.
 10. The shoe of claim 8, wherein said moisturepermeable upper layer comprises microporous and fully permeablematerial.
 11. The shoe of claim 8, wherein said waterproof lower layermakes contact with said membrane to which said lower waterproof layer isjoined at least in edge regions thereof by a sealing element joiningsaid at least one membrane and tread sole to said upper.
 12. The shoe ofclaim 8, wherein said upper is vapor-permeable.
 13. The shoe of claim 8,further comprising: a vapor-permeable insole; and a vapor-permeablefiller layer provided between said vapor-permeable insole and said atleast one membrane.
 14. The shoe of claim 8, wherein said moisturepermeable upper layer is permeable to heat and configured to allow heatexchange through said perimetric edge thereof.